Background: The Neuropsychiatric Inventory (NPI) is commonly used in dementia trials to quantify and qualitate changes in psychiatric symptoms. Methods: A questionnaire was administered to clinical trial raters to assess whether they were being trained to administer and score the NPI differently between clinical trial protocols. Results: Responses to the Survey indicated that there are differences between clinical trials protocols in how the instrument is administered and scored. Discussion: Clarification of administration and scoring rules are provided, including the behavioral sampling period, whether premorbid characteristics are considered. and what behaviors are considered in rating frequency, severity, and caregiver distress. (C) 2008 The Alzheimer's Association. All rights reserved.